Stuttgart, Germany, 25 April 2013 | DPA

Sam Stosur and Caroline Wozniacki have been bundled out on a difficult day for the seeds in the first round of the Porsche Grand Prix.

Sixth-seeded Stosur was beaten by former world No.1 Jelena Jankovic 6-4 6-4 on Wednesday at the WTA claycourt lead-up event to the French Open.

Wozniacki, seeded seventh and another ex-number one, was sent packing by Spain’s Carla Suarez-Navarro 7-6(6) 6-1.

Jankovic, who won in Stuttgart in 2008 and is currently ranked 18th, had the upper hand over Stosur from breaks in the ninth game of the first set and the third of the second. Stosur saved two match points at 5-3 but then hit a forehand long on Jankovic’s third chance.

It was Jankovic’s sixth win overall in eight meetings with Stosur but first on clay. The Serbian has shown good form lately with the Bogota title, Charleston final and Miami semifinal.

“She is really good on clay. It was very hard,” Jankovic said.

“I have played well over the last couple of months with some good wins.”

Stosur was gracious in defeat but reproached herself for a lacklustre performance.

“It was tough after a Fed Cup weekend, but that’s not an excuse,” she said.

“Jelena played consistently well and it’s pretty disappointing to lose. I have a few things to improve, but there is a bit of time before the French Open.”